The invention relates to an electrically-powered submersible robotic pool cleaner that is connected to a remote power supply by a floating power cable.
Self-propelled robotic pool cleaners are designed to traverse either a pre-programmed pattern or a random path across the bottom of the pool for the purpose of cleaning the bottom, and in some case, also the side walls of the pool. The submerged cleaner receives its power through a buoyant power cable attached to a fixed or portable power supply located in the proximity of the pool. When the cleaner is not in use, the power cable is typically gathered in the form of a loose coil for storage. The power cable is either manufactured to exhibit a tendency to form the coil, or will exhibit such a tendency after a period of use. However, the coils are easily displaced when the cable is stretched out upon the surface of the pool and attached to the power supply.
During operation of the pool cleaner, the repetitive turning motion of the cleaner back and forth from one side wall of the pool to the other and from end to end has a tendency to form coils in the floating power cable. If the size and configuration of the pool is known, it is possible to pre-program the operation of the pool cleaner to periodically reverse the pattern of movement in order to remove the coils that were formed in a prior programmed pattern of movement. However, this option is not always provided even in programmable pool cleaners, and is simply not possible in pool cleaners that are designed to move in a random path. As the coils are formed in the power cable, they have the effect of reducing the ability of the cable to extend its full length as is required to follow the path of the submerged moving cleaner. If the coiling continues, the intended movement of the cleaner along a prescribed path is interrupted, with the result that the cleaner cannot complete its cleaning cycle. In some cases, the cleaner is displaced from the bottom or side wall of the pool and becomes disabled or damaged by not being properly oriented. For example, if the pool cleaner is caused to float upside down to the surface of the pool, its intake system may no longer be able to draw water in necessary to cool the one or more motors that power the pumps and/or the mechanical drive mechanism, thereby resulting in damage to the motor and necessitating expensive repairs.
The problems associated with the coiling of the power cable are well known, and one solution to the problem has been to provide an electrical connector on the body or housing of the pool cleaner which permits that end of the power cable to rotate in response to the tension or forces transmitted by the power cable when the pool cleaner changes direction. As would be expected, these highly specialized electrical connectors constitute a substantial additional expense to the manufacturer, which is passed along in a higher cost of the finished cleaner to the ultimate purchaser. Especial care must be taken during the handling and storage of the pool cleaner to avoid damaging these swivel connectors. These swivelling connectors are also subject to much greater wear and tear than a fixed power cable connector and thereby result in additional expenses to the pool cleaner owner for eventual repair and/or replacement.
An other solution to the problem of cable coiling has simply been to disconnect the remote end of the cable from the power supply and to manually untwist the coils. As would be expected, this is a tedious and time-consuming task of manual labor which is particularly difficult to complete when the pool cleaner and cable are left in the water. The work of uncoiling the cable is reduced somewhat if the pool cleaner and attached cable are removed to the side of the pool. The task may be analogized to removing the coils from a garden hose which generally requires not only a twisting but a lifting of the hose from the ground in order to reduce the friction encountered.
It is therefore an object of the present invention to provide an efficient and easy to use apparatus and method for removing the undesired coils in a pool cleaner power cable that are formed during use.
Another object of the invention is provide such an apparatus that is relatively simple and inexpensive to manufacture and install on the cable, that requires no special care in use and in handling, and that is not easily damaged.
A further object of the invention is to provide an apparatus that can be installed on the power cable during assembly of the electrical connectors on the cable, or fitted to power cables that are already in use with swimming pool cleaners.
The above objects and other advantages are realized from the invention which broadly comprehends a grip assembly that is axially-mounted for rotation on the power cable at a position that is proximate an end of the power cable that can be disconnected from either the pool cleaner, or preferably, the power supply. The rotatable grip assembly includes one or more bearing means, the position of at least one portion of each of the bearing means being fixed with respect to the power cable. The grip assembly also includes a manual gripping member that contacts or can be brought into contact with the bearing means. In a preferred embodiment, the grip assembly is permanently mounted on the power cable; however, the grip assembly can also be produced in the form of a hinged or a longitudinally divided device that is releasably clamped onto the power cable for use and then removed.
At such time as undesired coils or twisting has occurred during use of the pool cleaner, the end of the power cable to which the grip assembly is attached is disconnected from the power supply or pool cleaner. A longitudinal or axial force is applied to the grip member in the direction of the free end of the cable. This axial force, or pulling on the free end, is translated by the bearing means into rotational movement of the power cable in the direction that will release the undesired coils and twisting of the power cable. The application of the axial force on the cable is discontinued when the cable ceases to rotate.
The method of the invention broadly comprehends:
(1) axially mounting a grip member for rotational movement on the power cable adjacent a first end of the cable that can be disconnected from either the power supply or the pool cleaner;
(2) disconnecting the power cable that has become twisted and coiled during its operation;
(3) manually applying an axial force to the exterior surface of the grip member in the direction of the free end of the cable against the resistive force of the coiled power cable, thereby causing the power cable to rotate with respect to the grip; and
(4) continuing to manually apply the axial force to the grip member until the relative rotation of the power cable ceases.